Dual hook blocks



4 Now l5, 1960 D. M. HULL DUAL Hoox BLOCKS Filed April 10, 1959 INVENTOR Duane M. Hull United States Patent DUAL HOOK BLOCKS Duane M. Hull, Alliance, Ohio, assigner to The Alliance Machine Company, a corporation of Ohio Filed Apr. 10, 1959, Ser. No. 805,508

4 Claims. (Cl. 254--168) This invention relates to dual hook blocks and particularly to a hook block separable into two portions operable from a single drive.

There are frequently instances where it is desirable to have a fast moving light hook block operable on the same crane with a heavy duty, slow moving hook block. In the past this has necessitated two separate drive systems and two separate hoisting drums. Generally, these two hoisting units were spaced apart on the crane frame, requiring heavier load bearing members as well as the additional expense of the second hoisting system.

I have invented a double block structure which provides both a light duty fast operating hook block independently operable on the same hoisting mechanism as the main heavy duty block. I preferably provide a crane frame, a hoisting drum on said frame, drive means on the frame for driving the hoisting drum, a cable on said drum extensible and retractable by rotation of said drum, sheave means on themain frame, a main hook block, a main hook on said block, sheave means in said hook block receiving said cable in multiple reeving with the sheave means on the main frame whereby said main hook block depends from said main frame, at least one part of sheave means on the hook block being movable independently of the main hook block, a secondary hook on said one part of the sheave means, lug means on said one part of the sheave means adapted to supportingly engage the main hook block when in contact therewith, locking means on the main frame releasably locking the main hook block -thereto whereby to selectively hold said main block against movement relative to the main frame and permit independent movement of the secondary hook and associated sheave. Preferably, the main hook block is provided with sheaves mounted on two separate shafts, one fixed for rotation in the main hook iblock, the other xed for rotation in a secondary hook block carrying lugs engageable on the main hook block to hold the two shafts in axial alignment and aid in supporting the main hook block. In a preferred form the -two ends of a single cable are fixed to the main hoisting drum passing over the sheaves on the main frame and the two hook blocks and equalized over an equalizer sheave mounted on the main frame.

In the foregoing general description, I have set out certain objects, advantages and purposes of my invention. Other objects, advantages and purposes will be apparent from a consideration of the following description and the accompanying drawings in which Figure l is a side elevation of a crane embodying the dual hook block structure of my invention;

Figure 2 is a section on the line II-II of Figure l;

Figure 3 is a view in elevation taken from the left of Figure 2.

Referring to the drawings, I have illustrated a conventional crane having a trolley movable on wheels 11 on tracks 12 of crane girders 13. The crane girders 'ice 13 are in turn movable on tracks d4 on the main building frame.

The trolley 10 is provided with a main frame 15 carrying a hoisting drum 16 driven by a drive motor The hoisting drum 16 is provided with a cable K18 whose two ends are fixed to the drum 16 and which is reeved over sheaves 19a, 19b, "19C and 19d on the main frame 15, an equalizer sheave 20' on the main frame 15 and over sheaves 21a, 2lb, 21C and 21d rotatable on a shaft 22 in a main hook block 23 depending below the main frame 15 and over sheaves 24a and 24h rotatable on a shaft 25 in a secondary hook block 26 movable selectively independently of the main hook block 23. The secondary hook block 26 is provided with lifting lugs 27 which are adapted to engage pads 28 on the main hook block 23 with the shafts 22 and 25 in axial alignment. A hook 29 depends from the secondary hook block 26. A hook 30 depends from the main hook block 23 to a level below hook 29. Locking latches 311 are mounted on the main frame :15 to engage supporting lugs 32 on the main hook block 23. The latches 31 are 4preferably operated by magnetic means (not shown) although they may be operated manually, pneumatically or by any other suitable means.

The operation of the dual hook block of my invention is as follows. When it is desired to use the main hook block 23, the latches 31 are opened and the hoisting drum 16 is rotated to pay out cable 18 over the sheaves 19a-c and 21a-d, 24a-b. This permits the entire main hook block to be lowered supported on sheaves 21a-d and on sheaves 24ab through the lifting lugs 27 and pads 28. When it is desired to use the secondary hook block for rapidly moving light loads, the main hook block 23 is raised and latches 31 are engaged beneath lugs 32. Cable 18 is then payed out by rotating hoist drum 16. This causes the cable to pass over all of the sheaves with relative movement of sheaves 21a-21d with respect to the main frame. Secondary hook block 26 is thereby independently rapidly lowered on sheaves 24a-b away from the main hook block 23.

While I have illustrated and described certain preferred embodiments of my invention it will be understood that the invention may be otherwise embodied within the scope of the following claims.

I claim:

l. In `a crane, a main frame, sheave means on the frame, a cable reeved on said sheave means, hoisting means acting on the cable to move it over said sheave means to elongate and retract said cable, a main hook block, a main hook on said block, sheave means in said hook block receiving said cable in multiple reeving with the sheave means on the main iframe whereby said main hook block depends from said main frame, at least one part of said sheave means on the hook block being movable independently of the main hook block, a secondary hook on said one part of the sheave means, lug means on said one part of the sheave means adapted to supportingly engage the main hook block when in contact therewith, locking means on the main frame releasably locking the main hook block thereto whereby to selectively hold said main hook block 4against movement relative to the frame and permit independent movement of the secondary hook yand associated sheave.

2. In a crane, a main frame, a hoisting drum on Said frame, drive means on the frame for driving the hoisting drum, a cable on said drum extensible and retractible by rotation of said drum, sheave means on the main frame, a main hook block, a main hook on said block, sheave means in said hook block receiving said cable in multiple reeving with the sheave means on the main frame whereby said main hook block depends from said main frame,

' 3 at least one part of said sheave means on the hook block being movable independently of the main hook block, a secondary hook on said one part of the sheave means, ylug means on said one part of the sheave means adapted to supportingly engage the main hook block when in contact therewith, locking means on the main frame releasably locking the main hook block thereto whereby to selectively hold said main hook block Aagainst movement relative to the frame and permit independent movement of the secondary hook and associated sheave.

3. In a crane, a main frame, a hoisting drum on the trame, drive means on the frame for driving the hoisting drum, a cable on said drum extensible and retractible by rotation of said drum, sheave means on the main frame, a main hook block depending from said main frame, a main hook on said block, sheave means in said main hook block receiving said cable in multiple reeving with the sheave means on the main frame, said sheave means on the hook block being mounted on two separate shafts, a secondary hook mounted on one of said shafts, said one shaft being movable independently of the main hook block, lug means on said one shaft yadapted to engage the main hook block whereby to partially support said main hook block when in contact therewith, locking means on the main frame releasably locking the main hook block thereto whereby to selectively hold said main block against movement relatively to the main frame and to permit independent movement of the secondary hook and associated sheaves.

4. In a crane structure as claimed in claim 3 an equalizer sheave on the main lframe, the cable being connected at its ends to the hoisting drum and supported intermediate its ends on said equalizer sheave on the main frame.

References Cited in the le of this patent UNITED STATES PATENTS 1,436,608 Rodier NOV. 21, 1922 2,463,394 King Mar. 1, 1949 2,752,120 Bogle June 26, 1956 

